A parametric study of Microporous Metal Matrix-Phase Change Material composite heat spreaders for transient thermal applications

Metal-PCM (Phase Change Material) composite heat spreaders offer a combination of high effective thermal conductivity and high density heat storage capability that are desirable for transient thermal management applications, especially in mobile and wearable electronic devices. In this study, we propose fabrication of microporous metal matrix (MMM)-PCM composite heat spreaders through electrodeposition of metal over a template of PCM microcapsules that result in composites with metal volume fraction of ~ 0.26. Effective thermal conductivity of these composites equal 74 W/m. K and 44 W/m. K for copper matrix and aluminum matrix respectively. Order of magnitude analysis for time response and thermal energy storage utilization performed on metal-PCM composites, as a function of metal volume fraction, shows that the optimal metal volume fraction range is 0.2-0.5 for the best thermal performance of metal-PCM composite heat spreaders. Furthermore, the temperature response of the MMM-PCM composite heat spreaders to a heat input showed that the use of PCM within a metal matrix can hold the device skin temperature below the ergonomic limit for long durations of time without sacrificing the time response.